Alappuzha (Kerala) | A Kerala State Road Transport Corporation (KSRTC) bus went up in flames in this coastal district on Friday morning, but none of the 44 passengers were hurt due to the swift response of the driver.

The incident occurred when the bus was between Kayamkulam and Alappuzha, police said.

The passengers escaped unhurt as the driver noticed a burning smell and asked everyone to get off the bus quickly, they said.

"The fire has been extinguished by the fire force. The cause of the fire is yet to be ascertained," an officer of Kayamkulam police station said.

Later, the driver of the bus told media that he had noticed a change in the engine sound and therefore, he parked the vehicle on the roadside.

Subsequently, he saw in the side view mirror that thick smoke was emanating from the back of the bus, the driver said.

"I asked everyone to get off immediately. There were 44 passengers on board at that time and around 20 of them were college students who were about to disembark at the next stop," he said.

The driver also said that the cause of the fire cannot be a leak from the diesel tank as it was located at the back of the bus.

"If it was a leak from the diesel tank, the fuel would leak away, but there would be no fire. The fire started in the engine. Something happened there," he said.

Visuals of the burning bus on TV channels showed thick smoke billowing out of the vehicle which was stopped on the busy national highway 66.

The bus was almost fully gutted in the fire.